Nipple erection post breast reduction. Is this permanent?

I had a fairly significant breast reduction 4 months ago (about 4 pounds off each breast) and I've noticed although I do have feeling in my nipples, the nipple on only one side shows any signs of reacting to anything, the other side doesn't seem to react at all, and actually seems puffy and slightly inverted. is this something that's going to likely be permanent, or is it possible that it will go back to "normal" with time? I'm not sure if it matters, but my surgeon did an anchor incision!